The hydrocyanation of butadiene using a nickel catalyst of the formula Ni[P(OR).sub.3 ].sub.4 is disclosed in Drinkard et al. U.S. Pat. No. 3,496,215. R in the Drinkard et al. formula may be an aryl of up to 18 carbon atoms. Examples XI and XII of said patent show reacting butadiene and hydrogen cyanide in the presence of a nickel catalyst of the above formula where R is phenyl.
A process for the preparation of zerovalent nickel complexes from elemental nickel are disclosed in Shook et al. U.S. Pat. No. 3,903,120. Among the various complexes disclosed by Shook et al. Are the mixed ligand complexes where the ligand is a mixed tri-meta- and para-tolyl phosphite--see Example 12 and Table 1, and complexes where the ligands are a mixture of ortho-tolyl and phenyl--see Example 54.
Hydrocyanation of pentenenitriles using a mixed ligand zerovalent nickel catalyst, in which the ligands are phosphite esters of mixtures of phenol, meta-cresol and para-cresol, are disclosed in Rapoport U.S. Pat. No. 4,330,483--see footnote 6 to the table appearing in Columns 5 and 6.
Some commercial processes for the hydrocyanation of butadiene have used zerovalent nickel catalysts of the formula Ni[P(OR).sub.3 ].sub.4 in which the ligands are phosphite esters of mixtures of meta- and para-cresol.